/Engine/Source/Editor/BlueprintGraph/Classes/BlueprintTypePromotion.h
Find the function that is the best match given the pins to consider. Ex: Given "Add" operator and an array of two Vector pins, it will return "Add_VectorVector"
static [UFunction](API\Runtime\CoreUObject\UObject\UFunction) * FindBestMatchingFunc ( [FName](API\Runtime\Core\UObject\FName) Operation, const [TArray](API\Runtime\Core\Containers\TArray)< [UEdGraphPin](API\Runtime\Engine\EdGraph\UEdGraphPin) * > & PinsToConsider )